Unit 5

sleep apnea

A sleeping disorder related to difficulty breathing while asleep.

drug

Any substance that causes a change in a person's physiological or psychological state.

theta brain waves

Electrical brain wave signals that indicate a light sleeping state.

alpha brain waves

Electrical brain wave signals that indicate a relaxed mental state.

delta brain waves

Electrical brain wave signals that indicate a state of deep sleep.

The amount of sleep needed for infants __________ as they age. decreases

In order to sleep, insects enter a state of __________. torpor

A drug is any substance that causes a change in a person's physiological or psychological state. Drugs fall into two categories-- legal and illegal. Legal drugs include medicine, tobacco, and alcohol. Each of these drugs is legal within limits. But certain usages of these drugs are illegal. For example, medicine can be illegal in a certain place, or if used by a particular person, like the use of medical marijuana, which is legal in some parts of the world and illegal in others. Medicines are drugs that are used to cure, treat, and prevent diseases or disorders. It can be bought in stores and pharmacies, and obtained through a prescription or over-the-counter. There are strict guidelines in the usage of medicine, however. Remember all medicines are drugs, but not all drugs are medicines. Tobacco and alcohol are legal to use but restrictions apply. In our society, you must be 18 years old to legally consume tobacco, and 21 years old to legally consume alcohol. Both can have harmful effects on the body as well. For example, alcohol can cloud your judgment, leading you to make poor or harmful decisions. And tobacco, like that found in cigarette smoke, has been linked to cancer and emphysema. Tobacco's also been linked to illnesses like diabetes, ulcers, and heart problems. Illegal drugs are grown, manufactured, processed or distributed without FDA regulation or approval. No one of any age may lawfully manufacture, possess, buy, or sell illegal drugs. Prescription drugs are illegal to sell to individuals without a prescription. They're illegal to sell without a license, to use without a prescription, or to buy without a prescription. If you use a prescription or over-the-counter drug in a way it wasn't intended, it becomes an illegal drug. That includes taking someone else's prescription or using household items to get high. Psychoactive drugs are chemical substances that affect experiential functioning such as behavior, mental functioning, and emotional state. They may be legal or illegal. Categories of psychoactive drugs that we'll be talking about in this section include narcotics, sedatives, stimulants, hallucinogen, cannabis, and alcohol. Narcotics are drugs that are used to relieve pain. They are highly addictive and distort reality for a short period of time. They can cause initial euphoria, but it's followed by depression of the nervous system. So it's important to monitor closely when they're prescribed, because they can lead to addiction. Effects of narcotics include euphoria, a feeling of well-being, relaxation, pain relief, and drowsiness. Possible consequences of narcotics include nausea or vomiting, confusion, slowed breathing, coma, or death. Some common narcotics and their street names include opium or block, morphine or dreamer, heroin or smack, and codeine or schoolboy. Sedatives are drugs that slow down the central nervous system. They are usually taken orally. Effects of sedatives include euphoria, reduced anxiety, loss of inhibitions, and drowsiness. And possible consequences include a slowed heart rate and breathing, memory loss, unconsciousness, or death.

Other consequences of sedatives include loss of coordination, slurred speech, confusion, or a coma. Common sedatives and their street names include barbiturates or yellow jackets and downers, tranquilizers or sleeping pills or candy, and Rohypnol, known as the date rape drug or roofies. Stimulants are drugs that speed up the central nervous system. This encompasses a broad category and include those substances that are prescribed, manufactured for substance abuse, and those found in over-the-counter decongestants, cigarettes, and caffeine. Effects of stimulants including increased alertness and energy, increased heart rate and blood pressure, increased breathing rate, and loss of appetite. Possible consequences can include nervousness and panic, increased aggression, kidney and liver damage, heart failure, or death. Stimulants can be smoked, snorted, injected, or swallowed. Common stimulants and their street names include cocaine and crack cocaine, known as blow or coke; amphetamines know as speed or crank; and methamphetamines known as crystal or ice. Stimulants cause the brain to release an abnormally large amount of brain stimulating chemicals which accelerate the functions in the brain and body. Hallucinogens are drugs that profoundly alter one's mood and distort one's sensory and perceptual experience. They're dangerous because they make it almost impossible to determine what is real and what is imagined. Effects of hallucinogens include sensory illusions, distortions of reality, dizziness, weakness, and enhanced emotions. Possible consequences include panic, self-injury, chronic mental disorders, flashbacks, and death. Common hallucinations and their street names include LSD, known as acid, dots, or buttons; and mushrooms, known as tops, magic mushrooms, or shrooms. Cannabis is the plant from which marijuana, hashish, and THC can be harvested. Effects include relaxation, feeling of well-being, distorted sense of time and distance, loss of short-term memory, and increased appetite. Possible consequences including impaired learning and memory, respiratory infection, and panic attack. Marijuana is a plant whose leaves, buds, and flowers are usually smoked for their intoxicating effects. The active chemical, THC, can be detected in one's urine for several weeks after use, and is one of the most widely used illegal drugs. Marijuana has many of the same toxins as cigarette smoke, and its long-term use is linked to things like bronchitis, damaged lung tissue, and an increased risk of lung cancer. Marijuana is also known as weed, pot, dope, blunt, grass or Mary Jane. Alcohol is a liquid drug created when grains, fruits, or vegetables are fermented. Effects of alcohol include euphoria, reduced anxiety, loss of inhibitions, or drowsiness. Possible consequences include a slowed heart rate and breathing, memory loss, unconsciousness, or death. Alcohol is technically a sedative, and is one of the most commonly used drugs in our society. Common alcohols include beer, wine, and spirits, such as rum, vodka, whiskey or brandy.

tolerance

Resistance to the effects of a substance, which the body develops naturally.

manifest content

The actual images, thoughts, and content of a dream.

sleep

A biological function and state of consciousness in which a person becomes relatively inactive and inattentive to stimuli.

addiction

A chronic medical condition associated with a physiological or psychological dependence on drugs.

sleep deprivation

A condition in which a person has not slept enough to gain rest within a time period.

sleep disorder

A condition that affects the ability to sleep or the quality of sleep.

REM sleep

A deep sleep during which the brain becomes very active, rapid eye motion occurs, and dreaming begins.

concentrative meditation

A meditative practice in which the practitioner focuses on a single image, sound, body function, or mantra.

transcendental meditation

A meditative practice in which the practitioner focuses on repeating a mantra to achieve inner peace.

mindful meditation

A meditative practice in which the practitioner is aware of all that flows through one's mind, but does not focus on any one thought.

night terrors

A parasomnia characterized by a sudden awakening from sleep in a terrified state; also known as sleep terrors.

somnambulism

A parasomnia in which the subject performs activities while asleep; also known as sleepwalking.

collective unconscious

A psychological construct representing human knowledge and memories inherited from an ancestral past.

narcolepsy

A rare sleeping disorder in which the subject experiences excessive sleepiness.

meditation

A ritualistic practice of clearing the mind in order to achieve a sense of relaxation and inner peace.

consciousness

A state of awareness or alertness in which the subject is cognizant of one's environment and self.

altered state of consciousness

A state of consciousness in which a person's level of awareness or thought process is affected.

hypnosis

A state of consciousness in which attention is focused very narrowly and the subject experiences increased suggestibility.

torpor

A state of rest in which a creature's heartbeat, body temperature, and awareness of the environment are drastically reduced, usually for hours at a time.

overdose

A strong physical reaction brought on by the intentional or unintentional consumption of a larger than usual amount of drugs.

posthypnotic suggestion

A suggestion made during a hypnotic trance that is intended to affect the subject's later conscious behavior.

biofeedback

A technique in which people use feedback from specialized machines to learn how to control their bodily mechanisms.

animal magnetism

According to Franz Mesmer, a magnetic energy in the human body that could be manipulated to cure illness.

During stage 2 sleep, most of the brain waves will be measured as __________ waves. theta

According to restorative theory, sleep repairs and restores the body's __________. energy

sleep debt

An accumulated deficiency of sleep; also known as sleep deficit.

insomnia

An extended bout of sleeplessness or trouble getting an adequate night's sleep.

hibernation

An extended state of torpor in which body functions slow down tremendously for long periods of time.

parasomnia

An undesired event that occurs during sleep.

Meditation means many things to many people. To some, it is synonymous with relaxation. To others, it is a spiritual practice, or a way to reach an inner peace. And to others, it's a health practice. It's used to seek a wholeness of spirit and body, and to seek to improve one's sense of who they are and how they fit into the world. Meditation is a ritualistic practice of clearing the mind in order to achieve a sense of relaxation and inner peace. It can be done while one is physically active or sedentary. There are many approaches and techniques for meditation. There are those associated with Eastern traditions, like Zen Buddhism and zazen. And those practiced in Western traditions, like those practicing Christianity, Sufism, or Judaism. Positions for meditation include relaxed shoulders, and one's spine should be straightened. In this position, you should concentrate, but not sleep. You can sit, stand, or walk while practicing meditation. There are two primary schools of meditation. Mindful meditation is one in which the practitioner is aware of all that flows through one's mind, but does not focus on any one thought. Concentrated meditation is one in which the practitioner focuses on a single image, sound, body function, or mantra. During mindful meditation, the focus should be on an empty mind. You can acknowledge your thoughts, but do not focus on them. During concentrative meditation, one is focused on intense contemplation. Usually, you focus on your breathing, a mental image, an object, or a word or phrase. One type of concentrative meditation technique is transcendental meditation. This is one in which the practitioner focuses on repeating a mantra to achieve inner peace. Meditation affects both the brain and body. Someone who practices meditation often experiences fewer negative emotions, like stress, anxiety, or depression. And they experience more positive emotions, like happiness or calmness. Generally, those that practice meditation show improvements in their body functioning and wellness. Scientists link these benefits to a difference in the way the brain functions while a person meditates. Many believe that meditation allows for peak experiences. This is a state of mind marked by intense feelings of well-being, joy, or complete self-fulfillment. This lines up nicely with the Buddhist belief that meditation is one path to nirvana. Nirvana is an ecstatic state in which one has reached perfect happiness or transcends any suffering. However, some studies show that there are no additive benefits to meditation when it's compared simple rest and relaxation. This doesn't mean that meditation isn't beneficial, just that it may not provide any additional benefits that cannot be achieved from adequate rest and relaxation alone. Meditation is often used in conjunction with other types of treatments, such as yoga, deep breathing, or anxiety medications.

Biofeedback is a technique in which people use feedback from specialized machines to learn how to control their bodily mechanisms. Biofeedback treats or helps to control heart rate, anxiety, muscle tension, pain, brain waves, blood pressure and skin temperature. It's based on the principles of learning. There must be a goal state, for example, if a patient wishes to control one's heart rate. So, monitors are hooked up to measure the heart rate, and the patient is assigned a task to complete on the computer where the biological measures are recorded by the computer. Next, the client adjusts his or her responses as the computer or data processing device reads back audio and visual information to the user. This helps the client focus their mind so they're able to adjust and control their responses. It can help lower blood pressure, help one relax and help one achieve a different physiological response. Advantages of biofeedback are that it can help control health problems such as anxiety, tension headaches, depression and high blood pressure. It's also a safe treatment. There are no reported side effects and no reported negative effects from using biofeedback. Those who support the use of biofeedback argue that some studies show that biofeedback therapies do reduce stress. Those who critique it argue that it cannot be effectively tested and that control groups are ineffective. Those who support biofeedback argue that it is safe for all populations. But those who critique the use argue that many studies show that there's marginal benefit, at best, from the use of biofeedback, and that it's difficult to design studies to measure its effectiveness.

Franz Anton Mesmer

Born 1734, died 1814; a French physician who claimed to be able to cure illness through the manipulation of magnetic energy and the use of trancelike states.

Jean Martin Charcot

Called the "father of modern neurology," he demonstrated hypnosis as a cure for "hysteria" and helped legitimize the practice of hypnosis.

psychoactive drugs

Chemical substances that affect experiential functioning such as behavior, mental functioning, and emotional state.

beta brain waves

Electrical brain wave signals that indicate an alert mental state.

Milton Erickson

Founded the American Society for Clinical Hypnosis and advocated for the use of hypnotherapy as a widespread practice.

Sleep is a biological function and state of consciousness in which a person becomes relatively inactive and inattentive to stimuli. Sleep is, though, a form of consciousness, and you can still perceive sensations from the environment when you're asleep. For example, the last time you were woken up from sleep. If you weren't conscious during sleep then these stimuli couldn't affect you. The brain remains active during sleep, but the type of brain waves change during sleep cycle. When we're awake we experience beta waves when we're alert and alpha weighs when we're more relaxed. When we're asleep, we first experience theta waves in stages 1 and 2, and then delta waves in stages 3 and 4. Scientists can measure the stages of sleep with EEGs, or electroencephalographs. The sleep cycle consists of 5 stages, and we go through four to six full cycles typically each night. In stage 1, it's a light sleep. It's easy to wake up. And we might experience hypnic jerks where we jolt ourselves awake. Theta waves dominate in stage 1 of sleep, and this is the shortest cycle. In stage 2 of sleep, our muscles contract and relax. Our heart rate and breathing pattern slow. And our body temperature falls. Sleep spindles also occur. These spindles are brief bursts of high frequency brain waves like you can see here. In stage 3 of sleep, this is the beginning of slow-wave sleep. Delta wave patterns begin here. They make up less than 50% of brain waves. In stage 4 of sleep, we also experience slow-wave sleep. This is the deepest sleep stage, and it assists in intense physical and psychological recovery. In stage 4 of sleep, delta waves occur more than 50% of the time. Stages 3 and 4 of sleep are very similar. Usually scientists differentiate between the two categories by saying that in stage 3, the delta waves occur less than 50% of the time, and the stage 4, the delta waves occur more than 50% of the time. Non-rapid eye movement sleep, or NREM sleep, is a portion of the same cycle consisting of sleep stages 1 through 4 that is dominated by delta and theta brain waves. Rapid Eye Movement sleep, or REM sleep, is a deep sleep during which the brain is very active, rapid eye motion occurs, and dreaming begins. In REM sleep, beta ways dominate. The brain waves of this stage closely resemble the alpha and beta patterns of an awakened person, and during REM sleep a person will experience vivid dreams. We can dream in other stages of sleep, but they'll be harder to remember without special preparations. This graph indicates a pattern of brain wave activity we experience as sleep progresses throughout the night. We start with alpha brain waves, then we progress to theta and then delta waves. At some point in a delta wave cycle, the brain waves become more active during the end of each cycle, and they spike back up like you can see here. When the brain waves spike, REM sleep is occurring. REM sleep occurs five to seven times during the average sleep cycle as indicated by the blue markings on the graph which you can see here. REM sleep gets progressively longer as a person goes through the sleep cycles. So during the first sleep cycle, REM sleep may only last 15 minutes, with stages 1 through 4 lasting about 75 minutes. By the end of the night, REM sleep can occur for up to 45 to 60 minutes, with stages 1 through 4 lasting only 45 minutes. A circadian rhythm is a natural cycle that the body undergoes. This is the physical, mental, and behavioral changes that follow an approximate 24 hour cycle, and its controlled by our biological clocks. Circadian rhythms regulate a number of very important biological functions like sleep and waking cycles, our blood pressure, heart rate, body temperature, and other hormonal functions. For example, between 3:00 and 5:00AM, our circadian rhythms will decrease our internal body temperatures to the lowest of the day. This is also a time when a normal sleeper is spending the most time in REM sleep. Jet lag can cause circadian rhythms to be disrupted. Jet lag is caused by crossing through time zones, and it can lead to disorientation and to trouble sleeping. Our circadian rhythms are usually synced to a 24 hour per day cycle. But when we change the time that the sun comes up or goes down by traveling through the time zones, our circadian rhythms need to reset.

It's important to realize that all living creatures have some form of sleep that they engage in at regular periods. This is part of the evidence that sleep is a necessary biological function. Dolphins have a number of issues when sleeping. For example, they're aquatic but they breathe air. They're conscious breathers, so they have to think about breathing. And there are many predators in the ocean, so how do they sleep? Dolphins rest only one half of their brain at a time. This is called unilateral sleep. While they're in this state, they can swim and move as if they're conscious. Dolphins, however, don't experience the elevated response thresholds that occur during human sleep. Ducks also rest half of their brain while sleeping. Ducks have eyes attached to the opposite sides of their brains. So they sleep with half of a brain and they sleep in a circle while in the wild. The ducks on the outer edge of the circle only rest the half that's facing the other ducks. That way they can rest and watch out for predators at the same time. Land mammals rest both sides of their brain at once. This is called bilateral sleep. Animal sleep patterns are not the same as human patterns. For example, a giraffe only sleeps 2 hours a day, where as a giant armadillo can sleep up to 18 hours a day. So why are there these differences? Well it might have something to do with the relative size of the animals or the size of their brains. Or it may be due to the differences in their environment, with adaptation to their environment having a prime correlation between the sleep intensity and duration. Some animals have adapted to their environments by entering a state of sleep unlike anything humans can do. This is called torpor. This is a state of rest in which a creature's heartbeat, body temperature, and awareness of the environment are drastically reduced, usually for hours at a time. Animals that engage in torpor include bears, mice, bats, and badgers. Hibernation in an extended state of torpor in which the body functions slow down tremendously for long periods of time. So sleep is necessary, but it differs among humans and animals. We know that sleep is a universal, biological need. But the role of sleep in the life of each organism has evolved as well. That's why humans and animals vary so much in the amount of sleep that they need, as well as the type of sleep that they engage in.

circadian rhythms

Physical, mental, and behavioral changes that follow an approximate 24-hour cycle.

An incidence that is caused by sleep and also occurs during sleep is known as a __________. parasomnia

Positive air pressure is a common treatment for ___________. sleep apnea

Philosophers have long argued about consciousness. They've debated over its definition, purpose, and existence. Some scientists believe that consciousness comes from the interaction of the brain's electrical signals. Consciousness, and the nature of consciousness, is still a big mystery. Consciousness is defined as the state of awareness or alertness in which the subject is cognisant of one's environment and self. There are four components to consciousness. The first is awareness of external stimuli and events. This is being aware of what's surrounding you in the environment. Next is awareness of an internal state. This can include a physiological state, like being too hot or too cold. Then is awareness of the self. This is being aware of your own perspective in relation to what you're experiencing. Finally is awareness of personal thoughts involving various experiences. This is anything about the self and life experiences, such as answering the question why am I here? In psychology, think of consciousness as the state of awareness, including your feelings, sensations, ideas, perceptions, and your sense of self. As you know, there are different types of consciousness. There are four distinctive features of consciousness: it's private, changing, continuous, and selective. Consciousness is private and always changing. It's private. Consciousness is a mental process and our experience of consciousness is solitary. You can't share your actual experiences with anyone. Consciousness is always changing. Our perceptions continue to evolve and change, and each experience affects the next. For example, you might hear the same song on the radio more than once, but you're never going to have the exact same reaction to the song as the first time you heard it. This is because each novel experience is unique. Consciousness is continuous and selective. It's continuous because it has no identifiable beginning or end to the experience, and our memory and experience are intertwined. Consciousness is selective. You can only focus on selective stimuli, and some things escape our notice. For example, the pressure of our shoes on our feet. Consciousness is like a stream, the interplay of the four features of being private, changing, continuous, and selective, gives us what is called the stream of consciousness, or that experience we have of having continuous changing experiences which flow naturally into each other but remain ours alone. Psychologists measure consciousness by studying brain waves. They do this with an electroencephalograph, or EEG. This is a machine that measures the electrical output of the brain using sensors attached to the skull, much like what you see here in this picture. There are four primary bands of brain waves that we experience: Beta waves, Alpha waves, Theta waves, and Delta waves. Beta waves indicate alertness This is the brain wave you would have if you were actively engaged in an activity or event. The waves are short and rapid. Alpha waves indicate relaxation. Here you can see the waves begin to slow down and spread out. Theta waves indicate a light sleep. We are conscious during sleep. For example, if someone were to clap their hands we would wake up. We are aware stimuli, just at a much higher threshold, so it takes more to get our attention. Finally, Delta waves indicate a deep sleep. These are the least active and slowest of the brain waves. We only enter Delta waves briefly during sleep, compared to the time we spend in Theta waves.

Sigmund Freud was a physician, psychiatrist, and psychologist. He created his own way of seeing and treating those with mental disorders, which she called psychoanalysis. He tried to cure people of disturbing and abnormal behavior. In doing so, Freud created one of the enduring insights into the nature of consciousness. Freud's three levels of consciousness included the conscious level, pre-conscious level, and unconscious level. The conscious level is a level of consciousness at which a person perceives thoughts and feelings. It's what we're aware of right now. Hopefully that includes this lecture, or feelings of hunger, or maybe people talking in the background. The pre-conscious level is the level of consciousness from which a person can recall memories or stored knowledge. These are quickly recalled when needed, such as where did I put the keys, or what did I eat today for lunch? At the unconscious level, this is a level of consciousness that contains repressed desires, wants, and impulses of which a person is unaware. According to Freud, the unconscious controlled much of your conscious behavior, whether you're aware of it or not. The unconscious contains things like past traumas, hidden hostilities, and desires you may not be proud of. Freud says the reason you're not aware of these things is because your brain is actively repressing these thoughts. Sometimes though, we have issues that arise from our compulsions that are caused by these unconscious desires. Freud's concept of consciousness is like an iceberg. At the top what is readily visible is our conscious level. Just below the surface but what's easily retrievable is the pre-conscious level. A majority of the iceberg is deep below the surface and hard to see or retrieve. This is the unconscious level. Freud believed that all levels of consciousness played a role in influencing our personality and behavior. There are two added levels of consciousness as well. Our non-conscious are the automatic body processes that function without conscious thought, like breathing or sweating. Sometimes these can rise to the level of consciousness. For example, we can control our breathing if we think about it. We can control the tempo or the flow. Our subconscious is sometimes called the unconscious, but they're not the same. Subconscious is the level of consciousness that picks up external signals our conscious mind does not notice. For example, we might retain the impression of an ad that we see briefly, leading us to want to buy that product later on.

Altered states of consciousness are defined as the state of consciousness in which a person's level of awareness or thought process is affected. There are many forms of altered states of consciousness, which include dozing and sleeping, dreaming, hypnosis, pathological states, meditative states, drug induced states, and biofeedback. Some cultures accept and encourage altered states, like those with ancient oracles, in Native American peyote rituals, when meditation is a spiritual exercise, those with drug use, those with peak experiences, or those experienced in flow states. In many cultures an oracle is a person believed to be able to speak for or deliver messages from the gods. They're found in many cultures and gave prophesies, fortunes and advice. They often entered ecstatic states that were either drug induced or induced by meditation. Native Americans have been using peyote in rituals for hundreds of years. Peyote is a cactus-like plant with psychotropic properties and is common in the Southwest. It has powerful hallucinogens known as mescaline, which can cause visions and extreme emotional responses. peyote rituals have been the subject of persecution and regulation for many years. Meditation can assist one in focusing on different goals. It's achieved through practicing mindfulness, concentration, and focusing on and regulating one's breath. Meditation differs from daydreaming, hypnosis, praying, and other relaxation techniques because it emphasizes maintaining alertness. It also aims at expanding one's self awareness and an increased state of integration and cohesiveness. Psychoactive drugs are often used to achieve altered states. Some drugs are illegal to own buy or sell, and drug legalization is an intensely contested issue, even today. Some drugs cause altered states that are not illegal, such as caffeine, aspirin, alcohol, and nicotine. Peak experiences were first described by Abraham Maslow. He's characterized them as a state of mind marked by intense feelings of well-being, joy, or completely self-fulfillment. Peak experiences can come in a variety of modes, including meditation, and the experiences appear to be unique to each person. A flow state was characterized by Mihaly Csikszentmihalyi, a professor at Claremont Graduate University. He described them as a state of joyful activity in which the subjects performs an action effortlessly and skillfully. Things that can occur when one is in the state of flow include deep concentration, be unworried about outside situations, a loss of time, and high confidence in the task we are focused on. It's important to remember that the ability or skill level of the individual must match the task but they are attempting. The person doing the task should have a high ability, but they should also be challenged. The task shouldn't be too easy or too hard. Culture is the key to acceptability. Modern Western societies generally prohibit or restrict substances that alter consciousness, such as alcohol, tobacco, marijuana, mescaline, and LSD. Altered states become an issue when cultures clash. Let's talk about peyote and its use with Native American rituals. Spanish conquistadores attempted to eliminate peyote use. The conquistadores had two main goals, to gain wealth for themselves and Spain, and to convert the indigenous peoples to Christianity. The peyote cult and its followers were a threat to this mission, so the conquistadores made peyote illegal and drove the cult underground. However, it reemerged in the 1860s, and was formally established as an organization in the 1910s. In Smith v. Oregon in 1990, two government employees were fired for the use of peyote in Native American rituals, and the Supreme Court upheld the firing of these two employees. However, in 1994, Congress passed legislation to protect the use of peyote in Native American rituals if it was for religious activity. These issues give rise to certain questions about the use of drugs and individual rights, and using drugs to achieve altered states of consciousness, especially when used for religious or cultural purposes.

Sleep is necessary. All creatures sleep. All animals who have been studied demonstrate sleep or sleep-like behaviors. Putting off sleep is harmful. You have to engage in recovery sleep if you put off sleep. This is sleeping even longer to make up for the sleep that you've missed. Sleep debt requires recovery sleep as well. The proportion of recovery sleep is related to the amount of sleep that's been put off. So the more sleep you put off, the more recovery sleep you'll need. The amount of sleep you need each night varies depending on what age you are. Infants need around 16 hours of sleep each day. Adolescents need between eight and nine hours of sleep each Adolescents need between eight and nine hours of sleep each night, and adults need between seven and eight hours. While these are general estimates, the individual amounts of sleep that a person needs could vary. There are different theories involving sleep and why we do it. One is that sleep restores and repairs, as seen in the restorative theory. Another idea is that sleep increases our chances for survival. This is seen in the energy conservation theory as well the adaptive-inactivity theory. One final idea behind why we sleep is that it improves cognition and development. This is seen in the growth process theory, information processing theory, and brain plasticity theory. One idea is that sleep repairs and restores. The restorative theory holds that while you're awake the body undergoes small but cumulative amount of damage. You deal with this when the body is completely at rest, or asleep. Sleep repairs and restores energy, neurons, brain tissue, and muscle growth. Because it's possible to get sick or die if you're sleep deprived, this throws weight behind this theory. Also, hormones necessary for body repair are released during sleep. Another idea as to why we sleep is that sleep increases our chances for survival. The energy conservation theory states that a reduction in energy while we're sleeping conserves energy resources. There was a time in the past when humans weren't the most dominant predator. And night our eyes were bad, the food was slim, and many animals would love to find easy prey like us. If we stop spending energy by sleeping, we may have more luck finding food in the morning, and we wouldn't get eaten at night. This theory gain support from the fact that most predators sleep more than the animals that are prey. It's bad to sleep too much if you're in danger of being eaten all the time. The adaptive-inactivity theory is another theory that explains that sleep increases our chances for survival. It holds that lack of activity increases the likelihood of survival. Another idea as to why we sleep is that improves cognition and development. Sleep influences the growth process because the growth hormone is released during sleep. As we age, adults release less of the growth hormone and less time is spent in deep sleep than when we're younger. This may explain why infants sleep more than adults. The information processing theory states that sleep may be necessary to process information and consolidate memories. So it strengthens and forms new neural networks which improves cognitive processes and our reasoning skills. Some theorize that people sleep to forget things that they learned during the day. It helps them remember important things by cleaning away all that's unnecessary. For example, think about practicing but never quite getting a skill right until you sleep on it for a night. A problem with this theory is how does the brain decide what information to keep and what information to get away? The brain plasticity theory states that sleep influences brain development. The brain's plasticity is insured and maintained by getting sleep daily. It allows portions of the brain to work in different ways which is crucial when the brain is developing. This might explain why people have problems functioning without much sleep. Finally, one last thought is that sleep allows for dreaming. Dreaming may be the adaptive tool sleep uses to accomplish goals. It possibly prolongs sleep. Dreams may help to organize the mind, and they may strengthen neural connections. So dreams may help humans solve problems and gain new insights into information, as well as rehearse different problems in their lives.

Many of us are affected by sleep issues. 60% of adults experiences sleep problems at least a few times a week, and 40% of adults say sleeplessness interferes with work at least a few days per month. 20% of adults say sleeplessness interferes with work at least a few days per week, and 69% of children experience sleep problems at least a few times a week. So losing sleep have consequences. Sleep deprivation is a condition in which one has not slept enough to gain rest within a time period. This could result in sleep debt. This is an accumulated deficiency of sleep. The longer sleep debts require more recovery sleep. So you can't stay up late all week and expect to sleep in one weekend and catch up on all your rest. It's important to remember, though, that sleep deprivation is not a sleep disorder. Sleep deprivation can occur without any disorder being present. The effects of sleep deprivation are cumulative. in state 1, you experience irritability, moodiness, and lack of restraint. The more sleep that is missed, the more that has to be made up. Cumulative sleep loss worsens mental and physical impairment. In stage 2 of sleep deprivation, you might experience apathy, slowed speech, flattened emotional responses, impaired memory, and an inability to focus or innovate. So, contrary to popular belief, staying up late to cram the night before an exam would actually hurt your test performance because you'd have impaired memory and an inability to focus. The body will eventually succumb to involuntary microsleeps. This usually occurs in stage 3. You might experience nodding off or hallucinations as well. The effects of sleep deprivation can be detrimental. There are many consequences like fatigue, weight gain, reduced ability to perform simple tasks, and poor performance at work or school. Sleep deprivation is really bad if you drive to work or school. You risk falling asleep at the wheel and potentially getting into an accident and hurting yourself or someone else.

Sleep problems are classified as either disorders or parasomnias many A sleep disorder is a condition that affects the ability to sleep or the quality of sleep. A parasomnia is an undesired event that occurs during sleep. In this section, we're going to talk about three sleep disorders-- insomnia, sleep apnea, and narcolepsy. We're also going to talk about three parasomnias-- nightmares, somnambulism, and night terrors. Insomnia is a catch all term for a variety of sleep problems. It's defined as an extended bout of sleeplessness or trouble getting an adequate night's sleep. Symptoms of insomnia include difficulty getting to sleep, difficulty staying asleep, or habitually poor sleep. One night of poor sleep does not mean you're suffering from insomnia. Generally, you must experience these symptoms for at least a month. Causes of insomnia include poor sleep hygiene, anxiety, depression, stress, and alcohol and drug use. And it's often treated by improved sleep hygiene or sleep aids. Sleep apnea is a sleeping disorder related to difficulty breathing while asleep. Symptoms of sleep apnea include snoring, tiredness or irritability while awake, and frequent wakening from sleep. Sleep apnea is caused by obesity, throat infections, enlarged tonsils, or weakening of the throat muscles, and is treated by positive airway pressure, rehabilitation, or medication. Narcolepsy is a rare sleeping disorder in which the subject experiences excessive sleepiness. In general, after a good night's sleep, we feel rested for about 11 to 12 hours after. Someone who suffers from narcolepsy may be tired shortly after, after maybe two to three hours instead of 11 to 12. Symptoms of narcolepsy include sleep attacks that occur usually without planning on part of the sleeper. Hallucinations, disturbed sleep, and memory problems are also symptoms of narcolepsy. We're not sure what causes narcolepsy, but it may be related to a chemical imbalance in the brain. There is no cure for narcolepsy, but stimulants can help subjects stay awake during the day. Nightmares are vivid and disturbing dreams that are experienced by a sleeper and that can interfere with rest. With nightmares, the dreams will wake the sleeper and interrupt sleep. Symptoms of nightmares are a vivid memory of the nightmare, anxiousness towards going asleep, and difficulty sleeping. Causes of nightmares are anxiety, a poor diet, and an extreme emotional experience, and they're often treated by improving the diet, counseling, or medication in more extreme cases. Somnambulism is a parasomnia in which the subject performs activities like walking while asleep. Symptoms of somnambulism are eyes being open while asleep, activity during sleep, confusion and disorientation upon awakening, and no memory of the incident while awakened. Causes of somnambulism are fatigue, lack of sleep, anxiety, mental disorders, and a medical reaction. It is OK to wake the sleeper if they're suffering from somnambulism. In fact, if someone is sleepwalking and headed toward danger, you definitely want to wake him up. Another type of treatment is tranquilizers or safety proofing that area they're sleeping in. Night terrors are a parasomnia that is characterized by a sudden awakening from sleep in a terrified state. These occur while the subject is sleeping, and they're very common in children. Symptoms include screaming or yelling while asleep, sitting up in bed, thrashing and kicking, or heavy sweating and breathing. Night terrors could be caused by a fever, lack of sleep, or emotional stress. If an adult is experiencing a night terror, it's usually related to something bigger like sleep apnea. Night tears are treated by comforting the subject, counseling, or medication.

There are contentious debates over dreams and what do dreams mean. Cultures all over the world interpret dreams differently. Some view them as important in reality and some do not. It's important to remember throughout this section that there's no correct way to interpret dreams. Many ancient cultures believed dreams were spiritual messages. The Babylonians felt that good dreams were from the gods or good spirits, whereas bad dream were from demons or evil spirits. Ancient Egyptians felt that gods revealed themselves in dreams, and demand religious acts, give warnings, or grand ritual or prophetic dreams. Ancient Hebrews felt that good dreams were from God, or Yahweh, and bad dreams were from demons or evil spirits. Many ancient cultures also believed that prophecies were contained in dreams. Most ancient civilizations believed in dreams as alternate realities. They were seen as gateways to a coexisting alternate reality or spirit world where one could communicate with gods, spirits, and evil spirits. Western cultures do not tend to put too much stock or thought into dreams. The general tendency in Western cultures is to attach those who put too much importance on their dreams with a stigma of being frivolous. But some exceptions exist. Eastern cultures still tend to view dreams of something special. The traditional Eastern interpretation of dreams is that they contain messages. They're portals into the spirit world which allow us contact with ancestors, and can contain hints of upcoming events such as good or bad omens. The motivated approach is the tendency of dreamers to interpret their own dreams based on their existing biases. People tend to attribute at least some significance to their own dreams. But people may not take the dreams of others as indication of special insight. For example, you may feel as if your own dream is significant, whereas another person's dream is interesting but inconsequential. Western society interprets dreams mostly according to Sigmund Freud and Carl Jung. Sigmund Freud and Carl Jung. This is the unconscious part of the mind which seeks out pleasure. Freud envisioned dreams as a window into the unconscious mind. For Freud, using clues from the dream state can help a psychologist determined hidden, unconscious desires that might be giving an individual real, psychological problems. Freud said dreams have two parts-- the manifest content, which is the actual images, thoughts, and content of a dream; and the latent content, which is the hidden, psychological meaning of a dream.

So Freud thought dreams contained manifest content. In this case, it could be crows or a talk with a childhood friend. He felt they also contained latent content, or the hidden meaning of the manifest content. So in this case, crows could represent a desire to improve one's habits. Or the talk with a childhood friend could represent a desire to escape adult pressures. Carl Jung believed dreams reflected an underlying human experience. He talked about the collective unconscious, which is a psychological construct representing human knowledge and memories inherited from an ancestral past. As a result of the collective unconscious, Jung theorized that all of humanity would respond to certain symbols in similar ways, especially when they're encountered in dreams. Jung also discussed archetypes. These are universally stimulating images and symbols recognized consciously and unconsciously by humanity. Archetypes gives meaning to humans across cultural boundaries and are a potent means of interpreting dreams and an unconscious mind. So from the dream example earlier, the manifest content would be the crows and a talk with a childhood friend. Jung might say that the crows represent the shadow, which represents an internal conflict. Or the talk with a childhood friend could be symbolic of the child, which represents a future rebirth, or gives us hope for the future. So Jung might say we fear our own natures, the repressed parts of our personality, but that we have hope for our future rebirth. Now let's compare similarities and differences between the theories of Freud and Jung. Freud believed that dreams point to past meanings and that symbols are usually erotic. Jung felt that dreams point to the past and future meaning, and that symbols are usually archetypes. Both Freud and Jung felt that dreams were valuable and that doctors must consult patients on their interpretations of dreams. Many cultures view dreams as separate from reality but still important. They cam be used to make predictions about the future or get messages from beyond.

Hypnosis is a state of consciousness in which attention is focused very narrowly and the subject experiences increased suggestibility. Under hypnosis, people will not do what they do not want to do, such as dangerous or immoral acts, or even positive acts. For example, you can't convince someone to quit smoking through hypnosis unless they actually want to quit smoking. The CIA has investigated hypnosis for use in interrogation but they found it unsuitable because it requires a trusting relationship between the hypnotist and subject. This cannot be formed if you force someone to undergo hypnosis. They also found that the recovered information might be unreliable. Being in a hypnotic trance is described as a state of focused attention. There's a lack of awareness of the surrounding environment. When someone is in a hypnotic trance, their muscles are relaxed, their eyes are closed or unfocused, and their breathing is slow. If the event is stressful, their muscles might be tight, they might become extremely agitated and have rapid breathing. Some common myths about hypnosis are that people are just faking hypnosis. The physiological responses that occur during hypnosis indicate that most are not lying. Other myths are that hypnosis allows people to relive the past, or that hypnotized people can remember the past more accurately. Really, hypnosis distorts memory with fantasy so subjects are more likely to inaccurately recall information. One final myth is that hypnotized people lose control over themselves. A subject is capable of ending a hypnosis session at any time or saying no while in a hypnotic state. So is hypnosis really a state of consciousness? Some brain waves are indistinguishable from normal waking brain waves. But other evidence suggests that hypnotised participants demonstrate changes in brain activity similar to those experiencing brain induce hallucinations or pain suppression. There are different degrees of hypnosis. About 25% of the population is difficult or almost impossible to hypnotize, but most people are able to be hypnotized if only mildly. People who are more open to suggestion are more easily hypnotized, This is correlated to level of intelligence, concentration, the ability to focus, willingness to be hypnotized, and one's control over their mental processes. Now let's discuss some theories explaining hypnotism. We'll talk about Barber and conscious control, Hilgard and the hidden observer, and Sarbin with role theory. Theodore Barber developed a theory of conscious control. He felt hypnosis is not a special state of consciousness. Really, suggestibility is the key to hypnosis benefits. Barber was a critic of hypnotism because he thought the benefits of hypnosis were from the power of suggestion. He found he could induce sleepiness by suggestion alone, and the power of suggestion worked in 20% of the people he tested. So he could someone quit smoking or sleep better through the power of suggestion. Ernest HIlgard claimed that consciousness was split into two separate streams of awareness. A hypnotic trance creates a hidden observer in the mind. He believed the observer could watch the body like an outside entity and could be used to suggest things to the body. The hidden observer also protects a person who's being hypnotized from doing anything the conscious mind wouldn't do. Theodore Sarbin developed social role theory. He felt that both the hypnotist and they hypnotized are playing roles, so hypnotism is basically play acting. People do what they expect hypnotized people to do. The trick is people aren't just role playing, they're role taking.

Some important figures in hypnosis include Franz Mesmer, James Braid, Jean Martin Charcot, Sigmund Freud, and Milton Erickson. Franz Anton Mesmer studied in Vienna and set up a medical practice in Paris. He believed the human body contain magnetic fluid, and if this fluid became misaligned, it would cause illness. Mesmer started using magnets to help direct and prevent blockages. He eventually came to believe that cures were due to his animal magnetism and stopped using magnets altogether. This animal magnetism was a magnetic energy in the human body that could be manipulated to cure illness. Mesmer believed every person had magnetisme animal, or raw vital energy. Mesmer would stare directly into people's eyes. He would channel his animal magnetism through his hand. And his patients believed themselves to be cured. Mesmer's acolytes and followers called themselves mesmerists. That's where we get the word mesmerize, which means to hypnotize. The end of Mesmer's influence came when a scientific panel tested Mesmer's claim that he could mesmerize trees. In his study, he used a blindfolded boy to identify the mesmerized tree in a grove. The boy went into a fit at each tree but none had been mesmerized. Mesmer's career was damaged as a result upon failing to provide support for his claim. James Braid was inspired by a traveling mesmerist. He began using trances in his own medical practice. These thinking trances were much like sleep. Braid also gave the discipline the name by which it's now known and coined the term hypnosis. This is derived from the Greek word for sleep. Jean Martin Charcot was a French neuroscientist. He became known as the father of modern neurology and demonstrated hypnosis could be used as a cure for hysteria. He helped legitimize the practice of hypnosis and believed hypnosis to be a neurological phenomenon. Sigmund Freud worked with Josef Breuer using hypnosis to treat World War I victims of shellshock. Eventually, Freud left and develop psychoanalysis. Freud believed hypnosis was a psychological phenomenon. Milton Erickson was a psychiatrist and clinical hypnotherapist. He founded the American Society for Clinical Hypnosis and created his own school of hypnotherapy. Erickson advocated for the use of hypnotherapy as a widespread practice.

peak experiences

State of mind marked by intense feelings of well-being, joy, or complete self-fulfillment.

sleep hygiene

The combination of habits and environmental factors that affect our sleep.

Drug effects are influenced by many factors including dosage, method of transmission, chemical composition of the drug, the user's psychology and physiology, and the location where the drug is taken. Methods of transmission include ingestion, or swallowing the drug; inhalation; direct contact, like through the skin; and intravenous, where drug is injected with a needle. After ingestion, drugs are absorbed into the bloodstream. Eventually they reach the neurons in the brain. They are able to pass through the blood-brain barrier and affect neurons and altering neurotransmitter activity. They are able to pass through this blood-brain barrier because they're as small as neurotransmitters. Neurotransmission is the communication between synapses using electrical nerve impulses. It sends chemical messages. Neurotransmitters are chemicals that send information to other neurons by attaching to neural receptors. Neural receptors are the protein structures on the surface of a neuron cell membrane where neurotransmitters bind to initiate communication. So these are neurotransmitters, and they bind to the receptor sites. The neurotransmitters of one neuron are received by the receptor sites of a neighboring neuron. This either continues to carry the signal on or stops neural communication. The synapse is junction where the transmission of information takes place. So the neurotransmitters are going to travel across the synapse, as you can see here. Reuptake is the process that prevents too much of any particular neurotransmitter from being present in a neuron. The brain rewards certain activities by releasing the neurotransmitter dopamine. Activities releasing dopamine naturally include exercise, eating, and sex. But drugs can interfere with the natural neurotransmitter activity. Drugs affect neurotransmission because they can increase the release of certain neurotransmitters. That can affect number and type of neurotransmitters produced in neurons and affect the ability of neurons to absorb neurotransmitters. Dopamine is a neurotransmitters that helps the brain control movement, emotional responses, and pain and pleasure activity. Stimulant affects the body's production and processing of dopamine. Amphetamines can increase levels of dopamine produced neurons and also affect the ability of neurons to absorb and reabsorb dopamine that's produced. That leads to an increase in dopamine levels across all neurons, causing the effects of the drugs that we feel. As drug use increases, more of the drug is needed to achieve the same effect. You build up a tolerance to the drug. Your body and mind become more dependent on the effects of the drug, and this leads to addiction.

The cycle of addiction starts with drug use, moves to tolerance, dependence, addiction, and then withdrawal, which can lead to more drug use. The initial use of drugs may provide one with no sensation at all. Some drugs effects are psychological in nature and depend on the experiences of the user. Drugs may also provide pleasure, relief from pain or discomfort, and changes in one's consciousness. Tolerance is the resistance to the effects of a substance that the body develops naturally. As the body becomes accustomed to a drug, the dosage must be increased to achieve the desired effect. Tolerance for each drug develops at different speeds. Because initial drug use has variable effects, it's difficult to estimate how soon someone will develop a tolerance for the drug. But we can estimate how tolerance will progress. It will progress slowly with drugs like hallucinogens, cannabis, and alcohol. It will progress quickly with drugs like narcotics, sedatives, and stimulants. Dependence is the overwhelming psychological or physiological need for a substance. Psychological dependence is when a person comes to believe that they need the drug. Physiological dependence is when a person's body becomes chemically dependent on the drug. Addiction is a chronic medical condition associated with a physiological or psychological dependence on drugs. It can result in loss of control, manifestation of severe consequences, and compromised brain function or brain disorder. Withdrawal is the physiological and psychological effects that one experiences when a drug is taken away. It may compel the addict to continue drug use. They have a need for regular drug use, an inability to stop using the drug, and must maintain a constant supply of the drug. They also spend all of their money on the drug. In addition, they might engage in risky behavior to get the drug, and use the drug as a coping mechanism. They might engage in risky behavior while under the influence, and their main focus is on getting and using the drug. In the most severe circumstances, drug addiction can lead to overdose, infectious disease, or suicide and death. Overdose is a strong physical reaction brought on by the intentional or unintentional consumption of a larger than usual amount of drugs. There is no safe way to measure dosages of illegal drugs, and they can be fatal. When sharing needles, small amounts of blood are transferred. This could lead to fatal infectious diseases like HIV, hepatitis b, and endocarditis. Endocarditis is an inflammation of the inside lining of the heart chambers and heart valves. Drugs also affect one's reasonable decision making skills, making infectious disease more likely to occur. Drug abuse can lead to suicide. Many drugs are depressants. Drugs also amplify pre-existing negative emotions and affect a person's ability to make sound judgments and assess risk. Once an addiction gains hold, loss of control can lead to extreme despair and withdrawal symptoms can be too overwhelming. Even drugs that are typically mood enhancers can be affected by the psychological state of the person taking the drug. For example, a person who's severely depressed may become suicidal under the effects of a drug, even a stimulant.

archetypes

The experience of images, thoughts, or emotional states as a result of brain activity during sleep.

dream

The experience of images, thoughts, or emotional states as a result of brain activity during sleep.

latent content

The hidden psychological meaning of a dream.

conscious level

The level of consciousness at which a person perceives thoughts and feelings.

preconscious level

The level of consciousness from which a person can recall memories or stored knowledge.

unconscious level

The level of consciousness that contains repressed desires, wants, and impulses of which a person is unaware.

dependence

The overwhelming psychological or physiological need for a substance.

withdrawal

The physiological and psychological effects when a drug is taken away.

NREM sleep

The portion of the sleep cycle consisting of sleep stages 1-4 that is dominated by delta and theta brain waves.

self-hypnosis

The practice of a person hypnotizing oneself for some purpose.

hypnotic analgesia

The practice of using hypnosis as a way to reduce the pain and discomfort typically caused by a medical condition.

hypnotic regression

The process of recovering hidden or forgotten memories through hypnosis.

motivated approach

The tendency of dreamers to interpret their own dreams based on their existing biases.

activation-synthesis hypothesis

Theory of dreaming that suggests dreams are caused by biological processes.

Brain waves never stop while we're sleeping, and during REM sleep our brain activity greatly increases. So when a person sleeps, the brain is still very active A dream is the experience of images, thoughts, or emotional states as a result of brain activity during sleep. Because the brain isn't switched off during sleep, a dream uses the capabilities of the brain to make us feel, see, and think just as if we're awake. Many dreams occur during all sleep stages, but especially during REM sleep. Each dream usually lasts from 5 to 35 minutes, depending on the sleep cycle we're in. Early dreams will last only about five minutes. In each sleep cycle, the length of dreams tends to increase, with the longest dreams occurring near the point of waking. Research indicates that most dreams are unexceptional or mundane. Dreams tend to be self-centered. They're typically about the dreamer and have a connection with the dreamer's life. Women tend to remember dreams more often than men. And men are more likely to dream about aggression and sexuality than women. In fact, about 1 in 10 male dreams involve sex, whereas only 1 in 30 female dreams involve sex. Dreams can be influenced by outside stimuli as well, so as noises, the temperature, or our feelings. Although many people today report color in their dreams, some research has indicated that those alive during the days of black and white television reported more black and white dreams. Most dreams have extensive visual components, but dreams also include sensations such as vision, taste, touch, and smell. In fact, the blind don't experience dreams visually unless they've lost their sight. Nonemotional dreams can be difficult to remember, and remembered dreams usually occur late in the sleep cycle or just before waking. Many dreams deal with mundane experiences, and these dreams are usually not remembered. For example, an office worker may report having dreamt about filing paper or making copies. These types of dreams are hard to remember upon waking after a full night's sleep. You usually have to wake up during the earlier stages of sleep to have a shot at remembering them. Some commonly reported dreams are being chased, sexual experiences, falling, school, teachers, or studying, or being late. Some scientists believe that this may be a remnant of our evolutionary past, where something like being chased is a biologically useful thing to be able to rehearse through dreams. Negative dreams are common is well. Research indicates that about 8 in 10 dreams contain a negative event or emotion. Women and children usually have more nightmares than men or adolescents and adults. And negative dreams are common after a trauma. People commonly report dreams involving limitation when pursuing a goal, or being attacked, chased, or rejected, or experiencing some sort of misfortune. Sleep researchers have found a clear link between the actions and thoughts that a person has during the day and the dreams they have at night. MIT researchers Matt Wilson studied sleep in rats who spent a significant time running a maze. Wilson hypothesized that dreams are a form of rehearsal and that they may have a role in improving the retention of important memories. The brain activity of the rats indicated the memories of the maze were replayed during sleep. The contents of dreams are affected by everyday life, such as our actions and thoughts. Here are some keys to remember dreams. Write down your dreams immediately after awakening. This is one of the most effective methods. Set an alarm to go off throughout the night and when you wake up, write down any dream you can remember. Conduct daily dream preparations, such as repeating something like, I will remember my dreams. This technique requires a lot of willpower to succeed, but it can work well, and can also be used to have lucid dreams. You could also participate in a sleep or dream study, where scientists record and analyze your sleep patterns.

There are different theories as to why we dream, which includes that dreams are wish fulfillment, they're a way tosolve problems, that they're just neurological side effects, that they're a way to process information, or that they aid with development. Sigmund Freud proposed that dreams were a mechanism for wish fulfillment, meaning that the unconscious mind is attempting to resolve some sort of conflict. He proposed that the unconscious mind has many repressed desires and wishes and that dreams allow these to be acted on without consequence. He then hypothesized that analyzing dreams can help make past traumas clear. Rosalind Cartwright proposed that when a person sleeps, they'll have lower inhibitions about their morals, values, and logic. So when we dream, we're free from distractions. Our dreams are also related to everyday events. So therefore, dreams allow people to creatively encounter their problems without conventional blocks. There is some anecdotal evidence for this theory, but other studies show that sleep can help people learn new information, which may credit sleep in formation of new understandings. Another theory about why we dream is that dreams are just neurological side effects. This is known as the activation-synthesis hypothesis. It's the theory of dreaming that suggests that dreams are caused by biological processes. The brain, which is active during sleep, is getting all sorts of inputs from different parts of the brain. So dreams are just side effects of neural activity. Criticisms of this theory are that it doesn't take into account the emotional component of dreams, that they often incorporate daily happenings, and that dreams also happen outside of REM sleep. Dreams could be ways to process information like daily information. They can be useful in sorting out situational circumstances and events and may reinforce memories that we need. Dreams may also help with memory consolidation. They can be useful for forming and rehearsing memories, and we can separate the memories we need from the ones that we don't. Dreams may also have weekend synaptic connections. Theorists propose that neural firing that occurs during dreaming could be related to this process. Some claim that dreams may be beneficial for brain maturation and development because they may help develop and preserve neural pathways. Because dream content often matures along with the current knowledge level, it suggests that they may promote cognitive development. So dreams reflect the current level of knowledge and comprehension that we're at.

How long does a dream typically last near the end of the sleep cycle, just before waking? about 30 minutes

When a creature or person practices an activity during the day, what is the typical effect on their dreams?